1. Field of the Invention
The present invention relates to a micromanipulator fine control apparatus which can remotely control microtools, such as glass electrodes under microscopes, by liquid pressure, such as oil pressure.
2. Description of Related Art
In the field of basic medical science or biotechnology, there are micromanipulators for treating cells in various manners, for example, retaining, suctioning, injecting and dividing organs of creatures, cellular textures and egg cells. The cells are treated in various ways by finely controlling the micromanipulator with microscopes. When an operator finely controls the micromanipulator by directly touching a control handle of the micromanipulator, his hand trembling may be multiplied and transmitted to the micromanipulator through a body frame. Therefore, the micromanipulator needs to be gently operated without hand trembling, which requires complicated operations, the greatest possible care and a lot of skills. In order to solve these problems, there has been known liquid-operated micromanipulators which can finely and remotely control using hydraulic pressure, e.g., oil pressure.
FIG. 1 is a schematic view showing the basic structure of a conventional cell treatment device.
In FIG. 1, the cell treatment device comprises a stage 83 for mounting a Petri dish 82 containing egg cells 81 dipped in a reagent therein, a fixed retaining unit 84 for fixedly retaining the cells 81, a micromanipulator 85 for carrying out the practical cell treatment, and an optical system 86 for observing images of the cells 81 irradiated with light. The cell treatment device is mounted on a vibration-proof mat 87.
The micromanipulator 85 is provided with various kinds of microtools 88, such as glass electrodes, corresponding to the type of cell treatment, and a three dimensional displacement mechanism for moving a tip of the microtool 88 in three dimensions. The three dimensional displacement mechanism is finely operated, e.g., with hydraulic pressure through ajoystick 89 which is controlled by an operator.
The joystick 89 comprises a control handle 92 vertically suspended from the distal end of a supporting frame 91 having a visor shape and a transmitting unit 94 for transmitting oscillation in two directions 93 (shown by arrows in FIG. 1) of the control handle 92. The joystick 89 is for finely controlling the two dimensional movement of the micromanipulator 85 by manipulating the control handle 92.
The control handle 92 has a converting unit 95 for converting the oscillation motion in two directions (indicated by arrows) 93 crossing at a right angle into a mechanical displacement in a horizontal plane.
In conventional devices, other than one with the suspended control handle, there is a device with the control handle vertically standing from the converting part 95. However, recently devices with a suspended control handle are widely used because the operators can operate the device at a lower position without raising their arms.
Further, there is a known device having a mechanism for finely controlling the vertical movement of an object to be treated in order to meet the requirement of vertical movement of an object to be treated in a three dimensional displacement mechanism.
In the system that the three dimensional displacement mechanism of the micromanipulator is actuated with hydraulic pressure such as oil pressure through the fine-control joystick, the operator tilts and moves the control handle of the joystick in the desired angle and direction to move the tip of the microtool mounted on the micromanipulator to the desired position while looking it through the microscope. Even when the operator only intends to horizontally move the microtool of the micromanipulator, the actual operation is to tilt the control handle of the joystick, which makes the operation difficult.
Furthermore, after the operator has moved the tip of the microtool to the desired position by tilting and moving the control handle of the joystick, when the operator lets go of the control handle, the control handle is moved a little since it is not held. Accordingly, the tip of the microtool is moved a little from the desired position.